The present invention is directed to ink compositions, and more specifically, the present invention relates to aqueous inks especially useful for thermal ink jet, and acoustic ink printing, reference for example U.S. Pat. No. 5,121,141, U.S. Pat. No. 5,111,220, U.S. Pat. No. 5,128,726, U.S. Pat. No. 5,371,531, and U.S. Pat. No. 5,528,384, the disclosures of which are totally incorporated herein by reference, including especially acoustic ink processes, such as an acoustic ink printer for printing images on a record medium. Also, the inks of the present invention may be useful as ink jet inks, and for thermal ink jet processes.
More specifically, the present invention is directed to substantially noncorrosive acoustic ink compositions, especially aqueous inks wherein there can be generated with such inks excellent developed images with acceptable image permanence, excellent projection efficiency on transparencies, superior waterfastness characteristics, for example waterfastness values of about 95 to about 100 percent, and excellent crease resistance, and wherein the inks need not contain certain salts, and moreover, wherein the inks reduce or minimize corrosion of, for example, ink jet heads by including in the inks an alkali metal halide, such as potassium iodide. Moreover, in embodiments of the present invention, there are provided inks that enable the elimination, or minimization of undesirable paper curl. The inks of the present invention in embodiments thereof are comprised of a colored vehicle and optionally a noncolored vehicle, reference U.S. Pat. Nos. 5,688,312; 5,667,568; 5,700,316; 5,747,554, the disclosures of which are totally incorporated herein by reference.